From fb708912d7767abd0dae007f0baa30d139154230 Mon Sep 17 00:00:00 2001
From: Kenearos <kenearos@googlemail.com>
Date: Tue, 7 Jul 2026 22:29:03 +0200
Subject: [PATCH] =?UTF-8?q?feat(auth):=20Story=201.2=20=E2=80=94=20normali?=
 =?UTF-8?q?zeEmail=20+=20Login-Token=20(SHA-256,=20einmalig,=2030min)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 server/auth.js      | 45 +++++++++++++++++++++++++++++++++++++++
 server/auth.test.js | 52 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 97 insertions(+)
 create mode 100644 server/auth.js
 create mode 100644 server/auth.test.js

diff --git a/server/auth.js b/server/auth.js
new file mode 100644
index 0000000..a94fe13
--- /dev/null
+++ b/server/auth.js
@@ -0,0 +1,45 @@
+const crypto = require('crypto');
+const { db } = require('./db');
+
+// Einmal-Token-Lebensdauer (Minuten). Scanner-sicher lang genug, aber kurz.
+const TOKEN_TTL_MIN = parseInt(process.env.TOKEN_TTL_MIN, 10) || 30;
+
+/** Identische Normalisierung für Speicherung UND Abgleich (case-insensitive). */
+function normalizeEmail(email) {
+  return String(email).toLowerCase().trim();
+}
+
+/** SHA-256-Hex. Nur der Hash landet in der DB; der Rohwert lebt im Link/Cookie. */
+function hashToken(raw) {
+  return crypto.createHash('sha256').update(String(raw)).digest('hex');
+}
+
+/**
+ * Erzeugt einen Einmal-Login-Token für userId, speichert nur den Hash + Ablauf,
+ * gibt den ROHWERT zurück (kommt in den Magic-Link).
+ */
+function createLoginToken(userId) {
+  const raw = crypto.randomBytes(32).toString('hex');
+  const expiresAt = new Date(Date.now() + TOKEN_TTL_MIN * 60 * 1000).toISOString();
+  db.prepare('INSERT INTO login_tokens (token_hash, user_id, expires_at) VALUES (?, ?, ?)')
+    .run(hashToken(raw), userId, expiresAt);
+  return raw;
+}
+
+/**
+ * Löst einen Roh-Token einmalig ein: prüft Hash + nicht abgelaufen + nicht verbraucht,
+ * markiert ihn als verbraucht und liefert { userId, email, isAdmin } — sonst null.
+ */
+function consumeLoginToken(raw) {
+  const now = new Date().toISOString();
+  const row = db.prepare(`
+    SELECT t.token_hash AS tokenHash, t.user_id AS userId, u.email, u.is_admin AS isAdmin
+    FROM login_tokens t JOIN users u ON t.user_id = u.id
+    WHERE t.token_hash = ? AND t.used_at IS NULL AND t.expires_at > ?
+  `).get(hashToken(raw), now);
+  if (!row) return null;
+  db.prepare('UPDATE login_tokens SET used_at = ? WHERE token_hash = ?').run(now, row.tokenHash);
+  return { userId: row.userId, email: row.email, isAdmin: !!row.isAdmin };
+}
+
+module.exports = { normalizeEmail, hashToken, createLoginToken, consumeLoginToken, TOKEN_TTL_MIN };
diff --git a/server/auth.test.js b/server/auth.test.js
new file mode 100644
index 0000000..ddfa35e
--- /dev/null
+++ b/server/auth.test.js
@@ -0,0 +1,52 @@
+const { test } = require('node:test');
+const assert = require('node:assert');
+const fs = require('fs');
+const os = require('os');
+const path = require('path');
+
+process.env.DATA_DIR = fs.mkdtempSync(path.join(os.tmpdir(), 'dp-auth-'));
+const { db } = require('./db');
+const { normalizeEmail, hashToken, createLoginToken, consumeLoginToken } = require('./auth');
+
+function makeUser(email = 'a@b.de', isAdmin = 0) {
+  const info = db.prepare('INSERT INTO users (email,is_admin,created_at) VALUES (?,?,?)')
+    .run(email, isAdmin, new Date().toISOString());
+  return Number(info.lastInsertRowid);
+}
+
+test('normalizeEmail: lowercase + trim', () => {
+  assert.strictEqual(normalizeEmail(' Foo@Bar.DE '), 'foo@bar.de');
+});
+
+test('createLoginToken speichert nur Hash; consume liefert Nutzer genau einmal', () => {
+  const uid = makeUser('roundtrip@x.de', 1);
+  const raw = createLoginToken(uid);
+
+  // Rohwert darf NICHT als token_hash in der DB liegen
+  assert.strictEqual(
+    db.prepare('SELECT 1 FROM login_tokens WHERE token_hash = ?').get(raw),
+    undefined,
+    'Rohtoken darf nicht als token_hash gespeichert sein'
+  );
+  assert.ok(
+    db.prepare('SELECT 1 FROM login_tokens WHERE token_hash = ?').get(hashToken(raw)),
+    'Hash muss gespeichert sein'
+  );
+
+  assert.deepStrictEqual(consumeLoginToken(raw), { userId: uid, email: 'roundtrip@x.de', isAdmin: true });
+  assert.strictEqual(consumeLoginToken(raw), null, 'zweite Einlösung → null');
+});
+
+test('abgelaufener Token → null', () => {
+  const uid = makeUser('expired@x.de');
+  const raw = 'deadbeef'.repeat(8);
+  db.prepare('INSERT INTO login_tokens (token_hash, user_id, expires_at) VALUES (?,?,?)')
+    .run(hashToken(raw), uid, '2000-01-01T00:00:00.000Z');
+  assert.strictEqual(consumeLoginToken(raw), null);
+});
+
+test('nicht-Admin: isAdmin === false', () => {
+  const uid = makeUser('plain@x.de', 0);
+  const raw = createLoginToken(uid);
+  assert.strictEqual(consumeLoginToken(raw).isAdmin, false);
+});